Borussia Dortmund coach Thomas Tuchel refused to divulge the reasons behind his decision to suspend top-scorer Pierre-Emerick Aubameyang for the Champions League clash with Sporting CP.
Tuchel's side did not miss the forward at Signal Iduna Park, as his replacement - Adrian Ramos - secured their progression into the knockout stages with a 12th-minute header.
However, Aubameyang's suspension, which will end on Thursday, sparked rumours that the Gabon striker could be set for a move away from the club in January should he fall out of favour with Tuchel, who claimed that he had "no choice" but to drop Dortmund's star man.
"It was very difficult to do without him," Tuchel said, before confirming Aubameyang will return to the squad for Saturday's Bundesliga encounter with Hamburg.
"But it was that I had no choice. The decision was made yesterday [Tuesday] afternoon. In the next game, he will be back.
"But, internal reasons means internal. I do not account for speculation."
Though Dortmund impressed for large spells of Wednesday's Group F meeting, Sporting could have snatched a point late on had Bryan Ruiz directed his close-range header on target.
And Tuchel was quick to praise Jorge Jesus' side, acknowledging that Dortmund found it difficult to adapt after he elected to change systems at the interval.
"The result, we take the positives from," he added. "We wanted four midfielders to control the game. Either the idea was not so good or the execution. Sporting were braver.
"It felt incredibly difficult for us. In no phase of that match did we play naturally.
"Defensively we made many mistakes. But we're through after four matchdays. Some players got minutes where it was only semi responsible to let them play. We like that result a lot."